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Re: Tesla coil formula



Original poster: Shaun Epp <scepp@xxxxxxx>

Peter,

This short path that you talk about known as self inductance, is exactly why the wire length is not the determining factor for resonance wavelength of a coil, it is the inductance of the coil itself that determines this. The inductance includes the magnetic flux that crosses adjacent conductors of the coil.

Shaun


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, December 07, 2005 2:21 PM
Subject: Re: Tesla coil formula


Original poster: "Peter Terren" <pterren@xxxxxxxxxxxx>

Jared
Your reasoning seems to be at odds with the rest of the world and scientific observation despite repeated posts from other members.
Electricity is not water or string and analogies can only take you so far.
Can you appreciate the possibility that current flow in the first turn of a coil can affect the last turn of a coil. Just like two transformers with one turn each? This can happen "at the speed of light". Now consider the current that is taking "the long way there" by travelling through many turns of a coil also at "the speed of light" but will take a lot longer to get there. This is where your analogy founders because it only accounts for "the long way there".

Sorry I don't know any maths.

Peter
http://tesladownunder.com/


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, December 07, 2005 12:42 PM
Subject: Re: Tesla coil formula


Original poster: Jared E Dwarshuis <jdwarshui@xxxxxxxxx>


Hi Steve

The equations we developed are all based on the mathematics of
standing waves.

(1) A standing wave always partitions the length of a uniform
medium in even intervals.

(2) A Standing wave is the superposition of a forward and
reflected waves.

(3) Velocity / wavelength = frequency,  is maintained with
standing waves.

Examination of the left side of our equation stipulates that:

 n/2 C/ Wire length = frequency.     n = 1/2, 2/2, 3/2, 4/2...

In order to fit standing waves into a length of  wire we must
partition it into quarter wave segments.

We could write this as an angular frequency (w)

(w) = 2pi n/2 C/wire     n= 1/2, 2/2,....

The right side of our equation is:

 (w) = 1/ square root of (LC)

We have modified our inductance to reflect the fact that for an
inductor the voltage A to B = - L di/dt

The mathematics of standing wave resonance guarantee that our voltage
from A to B is between quarter wave segments. ( if it were not so then
the inductance sums to zero for a half wave coil)

So for example, when we put a full wave length on an inductor, for the
sake of angular frequency we are only interested in the inductance
from one quarter of the windings.

We can generalize this as:

 L = u / 4pi  x ( wire / 2n)sqrd x (2n)/length   n = 1/2, 2/2, 3/2,
4/2...

Now we can say that:

2pi  n/2 C/w = 1/ sqrt ( (u/ 4pi) x ((wire length)sqrd / 2n length) x
Capacitance )

n = 1/2, 2/2, 3/2..

We must subtract the  self capacitance of the coil. So we use
Medhurst's  equation to sum the capacitance between the voltage
potentials of the quarter wave regions.

Fiddles also operate according to the conditions of standing wave
resonance, and must satisfy these conditions:

(1) A standing wave always partitions the length of a uniform
medium in even intervals.

(2) A Standing wave is the superposition of a forward and
reflected waves.

(3) Velocity / wavelength = frequency,  is maintained with
standing waves.



Respectfully: Jared Dwarshuis, Larry Morris